Transports do make a difference both in performance and longevity, its just mechanics.
An audio CD has to spin accurately at 500 rmp, so fast that it generates wind noise, and a CDP obviously has vibration to deal with. A CD transport also has to do 200 RPM accurately. Then there is the quality of the laser, the pickup electronics, the drawer mechanism.
A CD transport can be designed for high end audio, or it can be lowest common denominator used for any disposible optical application.
So if you want to play mp3s its no difference, if you want high-end audio it is a big differnce. Most transports you can find today are fairly low quality. There is a lot of error correction going on.
I have a ~$500 CD-1 which I believe is basically a $3000 California Audio Delta/Sigma or something close to that. It is very good. There may be better out there but I think this one has a very good transport.